Knife-sharpener.



No. 755,599. PATENTED MAR. 22, 1:904. F. H. SMITH & D. O. SASSEMAN.

KNIFE SHARPENER. APPLICATION FILED FEB. 9, 1903. N0 MODEL.

UNTTED STATns Patented. March 22, 1904.

PATENT Orricn.

FRED H. SMITH, OF OAKPARK, AND DAVID C. SASSEMAN, OF, CHICAGO,

ILLINOIS ASSIGNORS TO F. H. SMITH MANUFACTURING 00., OF CHI- CAGO, ILLINOIS, A CORPORATION.

KNIFE-SHARPENER.

SPECIFICATION forming part of Letters Patent No. 755,599, dated March 22, 1904.

Application filed February 9, 1903. Serial No. 142,493. (No model.)

,To all whom it 777/6Ly concern.-

Be it known that we, FRED H. SMITH, residing at Oakpark, and DAVID C. SASSEMAN, residing at Chicago, in the county of Cook and State of Illinois, citizens of the United States, have invented certain new and useful Improvements in Knife-Sharpeners, of which the following is a specification.

The present invention relates to that class I0 of sharpeners in which there are two cuttingdisks arranged in the same radial plane and in such relation to each other that their peripheries form an angle, the sharpening being done by drawing the blade across the converging faces of the cutters.

One object of the invention is to provide a knife-sharpener of the class above described with means whereby it may be steadied with one hand while the knife is manipulated with the other hand and whereby theknife is guided to the bite of the cutters. To these ends we provide the frame of the sharpener with a portion which extends upward a considerable distance above the cutters and is adapted to be 5 grasped by the hand, the upwardly-extending portion being provided with a narrow slot.

Another object of the invention is to cause the cutting-disks to revolve automatically and also to revolve simultaneously, or practically 3 so, or, to state it conversely, to prevent either of them from revolving any considerable distance independently of the other, to the end that when one disk moves, and thereby advances a fresh cutting-surface, the other disk will move with it with like result, whereby those portions of the two disks which are for the time being in active cutting positions will be equally sharp, or substantially so. To this end we provide the peripheries of the disks 4 with intermeshing spiral cutting-ribs pitched in opposite directions.

Another object of the invention is to provide a frame of inexpensive and simple and at the same time strong and durable construction having the upper extension already referred to.

To these ends the invention consists in the features of novelty that are hereinafter described, with reference to the accompanying drawings, which are made apart of this specification, and in which- Figure 1 is a front elevation of a knifesharpener embodying the invention. Fig. 2 is a side elevation thereof. Figs. 3 and A are horizontal sections thereof on the lines 3 3 and 4t 4, respectively, of Fig. 1.

The cutters are represented at A. Each of them consists of a disk or short cylinder the edge of which has spiral grooves of V shape, resulting in spiral ribs of similar shape. These ribs may have any desired pitch, and their summits form a succession of cutting edges. The ribs of the two disks are pitched right and left, respectively. The disks are arranged in the same radial plane and with their ribs intermeshing, so that neither of them can revolve any considerable distance independently of the other. mated, the result of this is that fresh cuttingsurfaces of both of them will be brought into operative positions simultaneously, or practically so. We are aware that cutters have been made of disks having intermeshing spiral ribs pitched in the same direction; but these are not the equivalent of cutters having intermeshing spiral cutting-ribs pitched in opposite directions. An advantage of the latter, over the former is that the drag of theblade will tend to revolve the disks, and thus automat ically bring fresh cutting-surfaces into play.

The disks are loosely mounted upon studs B, so that they may revolve freely independently thereof. The studs have reduced ends 5, which pass through perforations in the frame and have their outer ends upset, so that the two sides of the frame are clamped firmly against the shoulders resulting from the reduced portions of the studs. This has the advantage of spacing the two sides of the frame and positively preventing them from moving either inward or outward relatively to each other and at the same time avoiding the possibility of clamping the cutting-disks between them, thus leaving the disks perfectly free to revolve. The frame preferably consists of a base C, having suitable feet 0, adapted to rest As before intidirectly supported and a handle or knob surmounting them. Again, the entire frame is preferably made of two pieces of sheet metal cut and stamped to proper shape, the two parts being held together at bottom by the studs B, as already described, and at top by the knob C The standards are provided with narrow vertical slots D, through which the blade is introduced to the disks. These slots serve the double purpose of giving access to the cutters and of guiding the blade and maintaining it at the proper angle with relation to the cutters.

We desire to have it understood, however, that the invention in its broadest aspect is not limited to a frame of the precise construction above described. Its essential characteristic in this respect is a portion extending upward above the cutters and adapted to be grasped by the hand for steadying the sharpener while being used and having the narrow slot for receiving a guide or blade. It is manifest that the knob C is not essential to this purpose and that, if desired, the standards of the frame might be grasped directly.

Having thus described our invention, the following is what we claim as new therein and desire to secure by Letters Patent:

1. A knife-sharpener having two disks provided on their edges with spiral cutting-ribs and means for supporting said disks with their axes substantially parallel and with their ribs intermeshing, the ribs of the two disks being respectively right and left, substantially as described.

2. A knife-sharpener having two disks provided on their edges with spiral cutting-ribs and means including a frame for rotatively supporting said disks with their axes substantially parallel and with their ribs intermeshing, the ribs of the two disks being respectively right and left, the upwardly-extending portion of the frame being provided with a narrow slot for admitting the blade to the cutters and for guiding it, and a handle at the upper end of said upwardly-extending portion of the frame, substantially as described.

3. A knife-sharpener having in combination a frame having a base and two standards rising therefrom and having narrow slots for admitting and guiding the blade, means for connecting the standards at top, two cuttingdisks arranged between the lower portions of the standards, and studs upon which said disks are rotatively mounted, the standards being provided with openings through which said studs project and the ends of the studs being upset whereby they connect the lower portions of the standards, and a handle connecting the upper ends of said standards, substantially as described.

FRED H. SMITH. DAVID C. SASSEMAN. Witnesses:

AXEL SELANDER, L. M. HOPKINS. 

